In the Japanese population, 3% of patients with GIST harbored the PDGFRA D842V mutation, which is characterized by a poor response to imatinib, sunitinib, and regorafenib.23-25 In the NAVIGATOR phase I trial, avapritinib demonstrated an impressive overall response rate (88%) for PDGFRA D842V-mutated GISTs, leading to its approval by the US Food and Drug Administration.26 However, avapritinib is not approved in many countries, including Japan. Here, PDGFRA is linked to gastrointestinal stromal tumor.